There is known Open Service Gateway Initiative (OSGI) Frame Work that is a technology for a program distribution device to distribute a specific program to a gateway device. Here, the gateway device designates a program; the program distribution device distributes the designated program to the gateway device. When this technology is directed to a vehicle, there is a case that a program distribution device distributes to an in-vehicle gateway device a program that conducts an access to a vehicular electronic control unit (vehicular ECU).
Here, this vehicular ECU is differentiated into various kinds based on vehicle information such as vehicle kinds and model years, even if the same function is contained in the vehicular ECU. Therefore, the program distribution device needs to able to distribute the program that is handled by the in-vehicle gateway device without any problem even if the in-vehicle gateway device connects with any kind of the vehicular ECU. However, development required for this necessity becomes extremely wide-scaled to thereby pose a first problem.
Furthermore, when the program for conducting an access to a vehicular ECU is distributed from a program distribution device to an in-vehicle gateway device, there is a risk that the program is forged or altered by a third party or unauthorized person while being distributed. This possibly causes an unauthorized access to the vehicular ECU to thereby pose a second problem or significant obstruction against traveling of the vehicle. To solve the second problem, only the programs developed and verified by trusted developers can be distributed from the program distribution device to the in-vehicle gateway device. However, in this case, the developers need to be limited, so that programs are limited, accordingly. Otherwise, security that prohibits an access to the vehicular ECU can be adopted so that the program cannot be executed in the condition that the security is not secured. However, this poses another problem that no access to the vehicular ECU is practically allowed.